Fountain pen



M y 1934; H. H. POLK, JR 19,167

FOUNTAIN PEN Qrigjinal -Filed July 20, 1931 [WM/ [21 0M [2 64/7 zi wodzkfldj Reissued May 15, 1934 UNITED STATES PATENT OFFICE FOUNTAIN PENOriginal No. 1,926,405, dated September 12, 1933, Serial No. 551,913,July 20, 1931. Application for reissue March '12, 1934, Serial No.715,255

3 Claims.

My invention relates to that class of fountain pens in which ink or aircontained within the pen barrel is displaced from one side to the otherof the plunger during the stroke of the latter away from the pen, and apartial vacuum is established in the barrel and the ink or air isexpelled therefrom during the stroke of the plunger toward the pen, andwhereby the barrel is substantially filled with ink drawn into thebarrel by the partial vacuum when the plunger reaches its limit ofmovement toward the pen with a single movement of the plunger.

The object of my invention is to provide a fountain pen of this class ofsimple, durable and inexpensive construction, and of few parts.

' More specifically it is my object to provide a plunger for pens ofthis character in which the ink or air contained within the barrel willbe freely displaced from one side of the plunger to the other sidethereof during the stroke ofthe plunger away from the pen point, and atthe very beginning of the movement of the plunger toward the pen theplunger will. betightly sealed to the pen barrel, to

thereby create a maximum degree ofvacuum within the barrel behind theplunger and to expel the ink or air in front of the plunger during thestroke of the plunger toward the pen.

My-invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the objects contemplated areattained, as hereinafter more fully set forth, pointed out in my claims,and illustrated in the accompanying drawing, in which:

Figure 1 shows a longitudinal sectional view of I a fountain penembodying my invention with the plunger shown at its limit of movementtoward the pen point;

Fig. 2 shows an enlarged detail sectional view of" a portion of the penbarrel and the plunger in position therein. The dotted lines show theposi tion of the plunger disk during the displacement stroke of theplunger, and also the position of the plunger disk when movingtoward thepen point to create a partial vacuum within the barrel;

and

Fig. 3 shows an enlarged, detail, transverse, sectional view through thebarrel at the point adjacent to which the plunger is situated when atits limit of movement toward the pen.

Referring to the accompanying drawing, I have used the reference numeral10 to indicate generally the pen barrel of usual construction, having ahollow cylindrical interior. At one end is the pen point 11, and at apoint in the barrel near 1 the pen point there are a number of grooves12,

shown in Fig. 3, and whereby communication is established between theinterior of the pen barrel and the pen point through a passageway suchas 13 when the plunger is at its limit of movement toward the penbarrel.v g I At the end of the barrel opposite the pen point is a packing 14,and slidingly extended through this packing is the plunger rod 15. Ascrewcap 16 is preferably provided for covering the handle end of theplunger.

The plunger proper comprises a sleeve 17 screwed on the end of theplunger rod adjacent to the pen point, and formed on this sleeve is aplunger disk retaining member 18 of comparatively small diameter, andinclined outwardly and toward the pen point. Mounted upon this sleeve1'? is the plunger disk indicated generally by the numeral 19. This diskis formed of a resilient and slightly compressible material, such forinstance as rubber.

- This plunger disk is normally flat and made slightly larger indiameter than the interior of the barrel, so that when it is in its flatcondition it presses tightly against the interior of the barrel. It may,however, be moved a slight degree to position shown by dotted lines at23 in Fig. 2, and still maintain tight contact with the interior of thebarrel. When, however, it is moved to position shown by the dotted lines21 in Fig. 2, its periphery stands clear of the barrel so that ink orair may pass by it.

Mounted upon the sleeve 17 is a disk holding plate 22 of a diameterslightly less than that of the interior of the pen barrel, and havingits face adjacent to the diskinclined slightly in a direction away fromthe pen point.

This disk holding plate22 is fixed to the sleeve 17 so that it togetherwith the part 18 forms a means for clamping the central portion of thedisk firmly in position. p

In practical use, and assuming that there is -a small quantity of inkwithin the barrel and it is desired to refill it, the operator firstremoves the cap 16, then grasps the handle end of the plunger rod andmoves it in a direction away from the pen point. During this movementthe air and ink contained within the barrel will press upon the plungerdisk sufliciently to cause it to assume the position shown by the dottedlines 21, so that the air and ink may pass around the periphery of theplunger disk and occupy a position in the barrel on the opposite side ofthe plunger.

As soon as the plunger disk has reached its limit of movement away fromthe pen, then the plunger disk, on account of its resiliency, willspring back to a substantially fiat position with its periphery firmlyin engagement with the interior of the barrel. Then at the instant whenthe plunger is moved in a direction toward the pen point, the plungerdisk will form a tight connection with the interior of the barrel, andas the movement is continued, it will assume the position shown bydotted lines 23 in Fig. 2, and its periphery will be held firmly incontact with the interior of the barrel throughout the entire movementof the plunger toward the pen point, so that air or ink 'will beexpelled from the barrel infront of the plunger and a maximum degree ofvacuum will be created'within the entire barrel at the rear of theplunger.

By reason of the fact that the disk holding plate 22 is of a diameterslightly less than that of the interior of the pen barrel, that theplunger disk 19 is of a larger diameter than the interior of the barrel,andthat the face of the plate adjacent to the plunger disk 19 isinclined slightly in a direction away from the pen point, all of whichis hereinabove stated, a wedging action of said plunger disk 19 isobtained between the periphery of the plate 22 and the internal wall rrod 15 in one direction and such action provides a substantiallyair-tight engagement between the plunger and the wall. Then when theplunger disk reaches the grooves 12in the barrel, and assuming that thepen point is inserted in ink, the ink will be drawn into the pen pointand the passageway 12 to approximately 1111' the barrel.

Thus the complete operation of expelling the contents of the .barrel andthe filling of the barrel with ink is done with a single stroke of theplunger in one direction.

The efliciency and practicability of a device I of this kind isdependent upon the amount of vacuum which may be produced in the penbarrel upon a single stroke of the plunger toward the pen point, andhence it is essential that at the very start of the plunger movementtoward the pen point a tight connection is made between the plunger diskand the interior of the barrel.

I am aware that for somewhat analogous purposes plungers have beenemployed containing cup-shaped packings which will permit air or liquidto pass around them when moving in one direction and form a tightconnection with the interior of the barrel when being moved in theopposite direction, but with these cup-shaped packings it is necessaryto move them a greater or less distance before the cup-shaped packingforms a tight joint with the interior of the barrel', and hence anattempt to employ a packing of this character in a fountainpen wouldresult in a considerably less amount of vacuum being produced, and hencethe pen barrel would be only partly filled during a single stroke of theplunger.

with my improvement, however, and by employing a normally disk-shapedplunger disk,

the packing forms a tight connection with the barrel before and at thecommencement. of the stroke toward the pen point, and hence a maximumdegree of vacuuni is created during a single stroke of the plungertoward the pen point.

I claim as my invention:

1. An improved fountain pen comprising a hollow cylindrical barrel, apen at one end thereof, a groove formed on the interior of thbarrel nearthe pen point, the pen being formed with a passageway communicatingbetween said groove and the pen point, a plunger rod-slidingly mountedin the end of the barrel opposite the pen point, a plunger on theplunger rod comprising a flat disk formed of yielding .resilientmaterial of such diameter that when in position extending straightoutwardly from the plunger rod it will beslightly under compression, andwhen the plunger rod is moved in either direction the friction of theplunger against the pen barrel will cause its outer portion to inclinerearwardly relative to the direction in which the piston is moving,means secured to the piston rod on one'side of the piston for limitingsaid inclining movement to such position that the piston retains contactwith the pen barrel, and means secured to the piston rod at the oppositeside 'of the piston for engaging the central portion of the piston butpermitting said inclining movement to extend to such an amount as topermit the periphery of the piston to stand a spaced apart from the penbarrel.

2. The combination with a fountain pen having a hollow cylindricalbarrel and a pen point at one end thereof, of a plunger rod slidinglymounted in the other end thereof, a plungeron the plunger rod comprisinga normally flat disk formed of yielding resilientmaterial of a diameterlarger than the internal diameter of said' barrel whereby a movement ineither longitudinal direction will cause a rearward inclination of saidplunger relative to the direction of movement, means secured to saidplunger rod on one side of said plunger for forcing a substantiallyair-tight engagement of said plunger with said internal diameter uponmovement of said plunger rod in one direction, and means secured to saidplunger rod on the other side of said plunger for permitting a spacedrelation of said plunger with said internal diameter upon movement ofasaid plunger rod in the other direction.

'3. The combination with a fountain pen having a hollow cylindricalbarrel and a 'pen point at one end thereof, of a plunger rod slidinglyameter larger than the internal diameter of said barrel whereby amovement in either longitudinal direction will cause a rearwardinclination of said plunger relative to the direction of movement, a

plate secured to said plunger rod having a face for engaging one side ofsaid plunger, said plate being of a diameter less than the internal diameter of said barrel and said face being inclined in a direction awayfrom said plunger to afford a wedging action of said plunger betweensaid plate and theinternal 'wall of said barrel upon movement of saidplunger rod in one direction whereby a substantially air-tightengagementis obtained, and a plunger retaining member on the other side of saidplunger for permitting a spaced relation of said plunger withsaid,.internal wall upon movement of said plunger'in the otherdirection. J

HENRY H. POLK, JR.

